package network;

import java.io.IOException;
import java.net.*;
import java.util.Scanner;

/*
 * @author zzr
 * @date: 2025/04/18  18:02
 * @description:
 */
public class UdpEchoClient {

    private DatagramSocket socket = null;
    private String serverIp = null;
    private int serverPort = 0;

    public UdpEchoClient(String serverIp, int serverPort) throws SocketException {
        this.serverIp = serverIp;
        this.serverPort = serverPort;
        socket = new DatagramSocket();
    }

    public void start() throws IOException {
        System.out.println("启动，客户端");
        Scanner scanner = new Scanner(System.in);

        while (true) {
            // 可以打印一个 -> 来表示提醒 提示用户接下来要输入内容~
            System.out.print("->");
            // 1. 从控制台读取要发送的请求数据
            if (!scanner.hasNext()) {
                break;
            }
            String request = scanner.next();

            // 2.构造请求并发送
            DatagramPacket requestPacket = new DatagramPacket(request.getBytes(), request.getBytes().length,
                    InetAddress.getByName(serverIp),serverPort);
            socket.send(requestPacket);

            // 3. 读取服务器的响应
            DatagramPacket responsePacket = new DatagramPacket(new byte[4096], 4096);
            socket.receive(responsePacket);

            // 4. 把响应显示到控制台上
            String response = new String(responsePacket.getData(), 0, responsePacket.getLength());
            System.out.println(response);
        }
    }

    public static void main(String[] args) throws IOException {
        UdpEchoClient client = new UdpEchoClient("127.0.0.1", 9090);
        client.start();
    }
}
